- Add STANDARDS and HISTORY sections within the appropriate manpages
- Mention two USENIX papers within kqueue(2) and strlcpy(3)
Reviewed by: bcr (mentor)
Approved by: bcr (mentor)
Obtained from: NetBSD
MFC after: 7 days
Differential Revision: https://reviews.freebsd.org/D24650
libc cannot assume that aligned_alloc and free come from jemalloc, or that
any application providing its own malloc and free is actually providing
aligned_alloc.
Switch back to malloc and just make sure we're passing a properly aligned
stack into rfork_thread, as an application perhaps can't reasonably replace
just malloc or just free without headaches.
This unbreaks ksh93 after r361996, which provides malloc/free but no
aligned_alloc.
Reported by: freqlabs
Diagnosed by: Andrew Gierth <andrew_tao173.riddles.org.uk>
X-MFC-With: r361996
pthread_get_name_np() and pthread_set_name_np().
This re-applies r361770 after compatibility fixes.
Reviewed by: antoine, jkim, markj
Tested by: antoine (exp-run)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D25117
Some environments in which execvPe may be called have a limited amount of
stack available. Currently, it avoidably allocates a segment on the stack
large enough to hold PATH so that it may be mutated and use strsep() for
easy parsing. This logic is now rewritten to just operate on the immutable
string passed in and do the necessary math to extract individual paths,
since it will be copying out those segments to another buffer anyways and
piecing them together with the name for a full path.
Additional size is also needed for the stack in posix_spawnp(), because it
may need to push all of argv to the stack and rebuild the command with sh in
front of it. We'll make sure it's properly aligned for the new thread, but
future work should likely make rfork_thread a little easier to use by
ensuring proper alignment.
Some trivial cleanup has been done with a couple of error writes, moving
strings into char arrays for use with the less fragile sizeof().
Reported by: Andrew Gierth <andrew_tao173.riddles.org.uk>
Reviewed by: jilles, kib, Andrew Gierth
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D25038
If execve fails with ENOEXEC, execvp is expected to rebuild the command
with /bin/sh instead and try again.
The previous version did this, but overlooked two details:
argv[0] can conceivably be NULL, in which case memp would never get
terminated. We must allocate no less than three * sizeof(char *) so we can
properly terminate at all times. For the non-NULL argv standard case, we
count all the non-NULL elements and actually skip the first argument, so we
end up capturing the NULL terminator in our bcopy().
The second detail is that the spec is actually worded such that we should
have been preserving argv[0] as passed to execvp:
"[...] executed command shall be as if the process invoked the sh utility
using execl() as follows:
execl(<shell path>, arg0, file, arg1, ..., (char *)0);
where <shell path> is an unspecified pathname for the sh utility, file is
the process image file, and for execvp(), where arg0, arg1, and so on
correspond to the values passed to execvp() in argv[0], argv[1], and so on."
So we make this change at this time as well, while we're already touching
it. We decidedly can't preserve a NULL argv[0] as this would be incredibly,
incredibly fragile, so we retain our legacy behavior of using "sh" for
argv[] in this specific instance.
Some light tests are added to try and detect some components of handling the
ENOEXEC fallback; posix_spawnp_enoexec_fallback_null_argv0 is likely not
100% reliable, but it at least won't raise false-alarms and it did result in
useful failures with pre-change libc on my machine.
This is a secondary change in D25038.
Reported by: Andrew Gierth <andrew_tao173.riddles.org.uk>
Reviewed by: jilles, kib, Andrew Gierth
MFC after: 1 week
Copying the approach chosen in r309412. This fixes building the libc tests
on a macOS host since the macOS /bin/dd binary does not support status=none.
As there only seem to be two uses, this commit changes the two Makefiles.
If this becomes more common, we could also add a wrapper bootstrap script
that ignores status= and forwards the remaining args to the real dd.
Another alternative would be to remove the status flag and pipe stderr to
/dev/null, but them we lose error messages.
Reviewed By: brooks
Differential Revision: https://reviews.freebsd.org/D24785
This commit adds the priv(9) that waters down the sysctl to make it only
allow read(2) of a dirfd by the system root. Jailed root is not allowed, but
jail policy and superuser policy will abstain from allowing/denying it so
that a MAC module can fully control the policy.
Such a MAC module has been written, and can be found at:
https://people.freebsd.org/~kevans/mac_read_dir-0.1.0.tar.gz
It is expected that the MAC module won't be needed by many, as most only
need to do such diagnostics that require this behavior as system root
anyways. Interested parties are welcome to grab the MAC module above and
create a port or locally integrate it, and with enough support it could see
introduction to base. As noted in mac_read_dir.c, it is released under the
BSD 2 clause license and allows the restrictions to be lifted for only
jailed root or for all unprivileged users.
PR: 246412
Reviewed by: mckusick, kib, emaste, jilles, cy, phk, imp (all previous)
Reviewed by: rgrimes (latest version)
Differential Revision: https://reviews.freebsd.org/D24596
Historically, we've allowed read() of a directory and some filesystems will
accommodate (e.g. ufs/ffs, msdosfs). From the history department staffed by
Warner: <<EOF
pdp-7 unix seemed to allow reading directories, but they were weird, special
things there so I'm unsure (my pdp-7 assembler sucks).
1st Edition's sources are lost, mostly. The kernel allows it. The
reconstructed sources from 2nd or 3rd edition read it though.
V6 to V7 changed the filesystem format, and should have been a warning, but
reading directories weren't materially changed.
4.1b BSD introduced readdir because of UFS. UFS broke all directory reading
programs in 1983. ls, du, find, etc all had to be rewritten. readdir() and
friends were introduced here.
SysVr3 picked up readdir() in 1987 for the AT&T fork of Unix. SysVr4 updated
all the directory reading programs in 1988 because different filesystem
types were introduced.
In the 90s, these interfaces became completely ubiquitous as PDP-11s running
V7 faded from view and all the folks that initially started on V7 upgraded
to SysV. Linux never supported this (though I've not done the software
archeology to check) because it has always had a pathological diversity of
filesystems.
EOF
Disallowing read(2) on a directory has the side-effect of masking
application bugs from relying on other implementation's behavior
(e.g. Linux) of rejecting these with EISDIR across the board, but allowing
it has been a vector for at least one stack disclosure bug in the past[0].
By POSIX, this is implementation-defined whether read() handles directories
or not. Popular implementations have chosen to reject them, and this seems
sensible: the data you're reading from a directory is not structured in some
unified way across filesystem implementations like with readdir(2), so it is
impossible for applications to portably rely on this.
With this patch, we will reject most read(2) of a dirfd with EISDIR. Users
that know what they're doing can conscientiously set
bsd.security.allow_read_dir=1 to allow read(2) of directories, as it has
proven useful for debugging or recovery. A future commit will further limit
the sysctl to allow only the system root to read(2) directories, to make it
at least relatively safe to leave on for longer periods of time.
While we're adding logic pertaining to directory vnodes to vn_io_fault, an
additional assertion has also been added to ensure that we're not reaching
vn_io_fault with any write request on a directory vnode. Such request would
be a logical error in the kernel, and must be debugged rather than allowing
it to potentially silently error out.
Commented out shell aliases have been placed in root's chsrc/shrc to promote
awareness that grep may become noisy after this change, depending on your
usage.
A tentative MFC plan has been put together to try and make it as trivial as
possible to identify issues and collect reports; note that this will be
strongly re-evaluated. Tentatively, I will MFC this knob with the default as
it is in HEAD to improve our odds of actually getting reports. The future
priv(9) to further restrict the sysctl WILL NOT BE MERGED BACK, so the knob
will be a faithful reversion on stable/12. We will go into the merge
acknowledging that the sysctl default may be flipped back to restore
historical behavior at *any* point if it's warranted.
[0] https://www.freebsd.org/security/advisories/FreeBSD-SA-19:10.ufs.asc
PR: 246412
Reviewed by: mckusick, kib, emaste, jilles, cy, phk, imp (all previous)
Reviewed by: rgrimes (latest version)
MFC after: 1 month (note the MFC plan mentioned above)
Relnotes: absolutely, but will amend previous RELNOTES entry
Differential Revision: https://reviews.freebsd.org/D24596
One of the error descriptions referred to permissions; in context the
meaning was probably clear, but the prot values are properly called
protections.
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Keep link_map l_addr binary layout compatible, rename l_addr to l_base
where rtld returns map base. Provide relocbase in newly added l_addr.
This effectively reverts the patch to the initial version of D24918.
Reported by: antoine (portmgr)
Reviewed by: jhb, markj
Tested by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D24946
It previously returned the object map base address, while all other
ELF operating systems return load offset, i.e. the difference between
map base and the link base.
Explain the meaning of the field in the man page.
Stop filling the mips-only l_offs member, which is apparently unused.
PR: 246561
Requested by: Damjan Jovanovic <damjan.jov@gmail.com>
Reviewed by: emaste, jhb, cem (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D24918
functionality first appeared in FreeBSD.
Submitted by: Gordon Bergling gbergling_gmail.com
Approved by: bcr
Differential Revision: https://reviews.freebsd.org/D24677
Attempted to clean up the language around "this is a malloc'd object." May be
passed as a parameter to free(3) is a bit obtuse.
Sponsored by: Dell EMC Isilon
This option was added as a transition aide when symbol versioning was
first added. It was enabled by default in 2007 and is supported even
by the old GPLv2 binutils. Trying to disable it currently fails to
build in libc and at this point it isn't worth fixing the build.
Reported by: Michael Dexter
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D24637
sendto(2), sendmsg(2) and sendmmsg(2) return ENOTCONN if a destination
address is specified and the socket is not connected and the socket
protocol does not automatically connect ("implied connect"). Document
that. Also document the fact that the destination address is ignored
for connection-mode sockets if the socket is already connected.
PR: 245817
Submitted by: Erik Inge Bolsø <knan-bfo@modirum.com>
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D24530
Contrary to the kevent man page, EV_EOF on a fifo is not cleared by
EV_CLEAR. Modify the read and write filters to clear EV_EOF when the
fifo's PIPE_EOF flag is clear, and update the man page to document the
new behaviour.
Modify the write filter to return the amount of buffer space available
even if no readers are present. This matches the behaviour for sockets.
When reading from a pipe, only call pipeselwakeup() if some data was
actually read. This prevents the continuous re-triggering of a
EVFILT_READ event on EOF when in edge-triggered mode.
PR: 203366, 224615
Submitted by: Jan Kokemüller <jan.kokemueller@gmail.com>
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D24528
In r326576 ("use @@@ instead of @@ in __sym_default"), an earlier version of
the phabricator-discussed patch was inadvertently committed. The commit
message claims that @@@ means that weak is not needed, but that was due to a
misunderstanding of the use of weak symbols in this context by the submitted
in the first draft of the patch; the description text was not updated to
match the discussion. As discussed in phabricator, weak is needed for
symbol interposing because of the behavior of our rtld, and is widely used
elsewhere in libc.
This partial revert restores the approved version of the patch and permits
symbol interposing for openat.
Reported by: Raymond Ramsden <rramsden AT isilon.com>
Reviewed by: dim, emaste, kib (2017)
Discussed with: kib (2020)
Differential Revision: https://reviews.freebsd.org/D11653
Revert r354606 to restore r354605.
Apply one line from jemalloc commit d01b425e5d1e1 in hash_x86_128()
to fix the build with gcc, which only allows a fallthrough attribute
to appear before a case or default label.
Submitted by: jasone in r354605
Discussed with: jasone
Reviewed by: bdrewery
MFC after: never, due to gcc 4.2.1
Relnotes: yes
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D24522
If the index we're trying to convert is 0 we can avoid a potentially
expensive call to getifaddrs(). No interface has an ifindex of zero, so
we can handle this as an error: set the errno to ENXIO and return NULL.
Submitted by: Nick Rogers
Reviewed by: lutz at donnerhacke.de
MFC after: 2 weeks
Sponsored by: RG Nets
Differential Revision: https://reviews.freebsd.org/D24524
In the below-referenced PR, a case is attached of a simple reproducer that
exhibits suboptimal behavior: EVFILT_READ and EVFILT_WRITE being set in the
same kevent(2) call will only honor the first one. This is, in-fact, how
it's supposed to work.
A read of the manpage leads me to believe we could be more clear about this;
right now there's a logical leap to make in the relevant statement: "When
passed as input, it forces EV_ERROR to always be returned." -- the logical
leap being that this indicates the caller should have allocated space for
the change to be returned with EV_ERROR indicated in the events, or
subsequent filters will get dropped on the floor.
Another possible workaround that accomplishes similar effect without needing
space for all events is just setting EV_RECEIPT on the final change being
passed in; if any errored before it, the kqueue would not be drained. If we
made it to the final change with EV_RECEIPT set, then we would return that
one with EV_ERROR and still not drain the kqueue. This would seem to not be
all that advisable.
PR: 229741
MFC after: 1 week
This avoids passing garbage to sigprocmask() if the jump buffer is
invalid.
Reviewed by: mhorne
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D24483
This saves a system call and avoids one of the (relatively rare) cases
of the kernel exporting pointers via sysctl.
As a temporary measure, keep the sysctl support to allow limited
compatability with old kernels.
Fail gracefully if ps_strings can't be found (should never happen).
Reviewed by: kib
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D24407
This will be used by setproctitle().
Reviewed by: kib
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D24407
This pattern is used in callbacks with void * data arguments and seems
both relatively uncommon and relatively harmless. Silence the warning
by casting through uintptr_t.
This warning is on by default in Clang 11.
Reviewed by: arichardson
Obtained from: CheriBSD (partial)
MFC after: 1 week
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D24425
Include a temporarily compatibility shim as well for kernels predating
close_range, since closefrom is used in some critical areas.
Reviewed by: markj (previous version), kib
Differential Revision: https://reviews.freebsd.org/D24399
sonewconn() emits debug-level messages when a listen socket's queue
overflows. Currently, sonewconn() tracks overflows on a global basis. It
will only log one message every 60 seconds, regardless of how many sockets
experience overflows. And, when it next logs at the end of the 60 seconds,
it records a single message referencing a single PCB with the total number
of overflows across all sockets.
This commit changes to per-socket overflow tracking. The code will now
log one message every 60 seconds per socket. And, the code will provide
per-socket queue length and overflow counts. It also provides a way to
change the period between log messages using a sysctl.
Reviewed by: jhb (previous version), bcr (manpages)
MFC after: 2 weeks
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D24316
This had been introduced to ease any pain for using slightly older kernels
with a newer libc, e.g., for bisecting a kernel across the introduction of
shm_open2(2). 6 months has passed, retire the fallback and let shm_open()
unconditionally call shm_open2().
Stale includes are removed as well.
arc4random.c: In the incredibly unbelievable circumstance where
_rs_init() fails to allocate pages, don't call abort() because of
corefile data leakage concerns, but simply _exit(). The reasoning
is _rs_init() will only fail if someone finds a way to apply
specific pressure against this failure point, for the purpose of
leaking information into a core which they can read. We don't
need a corefile in this instance to debug that. So take this
"lever" away from whoever in the future wants to do that.
arc4random.3: reference random(4)
arc4random_uniform.c: include stdint.h over sys/types.h
close_range(min, max, flags) allows for a range of descriptors to be
closed. The Python folk have indicated that they would much prefer this
interface to closefrom(2), as the case may be that they/someone have special
fds dup'd to higher in the range and they can't necessarily closefrom(min)
because they don't want to hit the upper range, but relocating them to lower
isn't necessarily feasible.
sys_closefrom has been rewritten to use kern_close_range() using ~0U to
indicate closing to the end of the range. This was chosen rather than
requiring callers of kern_close_range() to hold FILEDESC_SLOCK across the
call to kern_close_range for simplicity.
The flags argument of close_range(2) is currently unused, so any flags set
is currently EINVAL. It was added to the interface in Linux so that future
flags could be added for, e.g., "halt on first error" and things of this
nature.
This patch is based on a syscall of the same design that is expected to be
merged into Linux.
Reviewed by: kib, markj, vangyzen (all slightly earlier revisions)
Differential Revision: https://reviews.freebsd.org/D21627
This is the foundational change for the routing subsytem rearchitecture.
More details and goals are available in https://reviews.freebsd.org/D24141 .
This patch introduces concept of nexthop objects and new nexthop-based
routing KPI.
Nexthops are objects, containing all necessary information for performing
the packet output decision. Output interface, mtu, flags, gw address goes
there. For most of the cases, these objects will serve the same role as
the struct rtentry is currently serving.
Typically there will be low tens of such objects for the router even with
multiple BGP full-views, as these objects will be shared between routing
entries. This allows to store more information in the nexthop.
New KPI:
struct nhop_object *fib4_lookup(uint32_t fibnum, struct in_addr dst,
uint32_t scopeid, uint32_t flags, uint32_t flowid);
struct nhop_object *fib6_lookup(uint32_t fibnum, const struct in6_addr *dst6,
uint32_t scopeid, uint32_t flags, uint32_t flowid);
These 2 function are intended to replace all all flavours of
<in_|in6_>rtalloc[1]<_ign><_fib>, mpath functions and the previous
fib[46]-generation functions.
Upon successful lookup, they return nexthop object which is guaranteed to
exist within current NET_EPOCH. If longer lifetime is desired, one can
specify NHR_REF as a flag and get a referenced version of the nexthop.
Reference semantic closely resembles rtentry one, allowing sed-style conversion.
Additionally, another 2 functions are introduced to support uRPF functionality
inside variety of our firewalls. Their primary goal is to hide the multipath
implementation details inside the routing subsystem, greatly simplifying
firewalls implementation:
int fib4_lookup_urpf(uint32_t fibnum, struct in_addr dst, uint32_t scopeid,
uint32_t flags, const struct ifnet *src_if);
int fib6_lookup_urpf(uint32_t fibnum, const struct in6_addr *dst6, uint32_t scopeid,
uint32_t flags, const struct ifnet *src_if);
All functions have a separate scopeid argument, paving way to eliminating IPv6 scope
embedding and allowing to support IPv4 link-locals in the future.
Structure changes:
* rtentry gets new 'rt_nhop' pointer, slightly growing the overall size.
* rib_head gets new 'rnh_preadd' callback pointer, slightly growing overall sz.
Old KPI:
During the transition state old and new KPI will coexists. As there are another 4-5
decent-sized conversion patches, it will probably take a couple of weeks.
To support both KPIs, fields not required by the new KPI (most of rtentry) has to be
kept, resulting in the temporary size increase.
Once conversion is finished, rtentry will notably shrink.
More details:
* architectural overview: https://reviews.freebsd.org/D24141
* list of the next changes: https://reviews.freebsd.org/D24232
Reviewed by: ae,glebius(initial version)
Differential Revision: https://reviews.freebsd.org/D24232
This is an application of the kernel overflow fix from r357948 to
userspace, based on the algorithm developed by Bruce Evans. To keep
the ABI of the vds_timekeep stable, instead of adding the large_delta
member, MSB of both multipliers are added to quickly estimate the overflow.
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
